Threading toolholder



NOV. 14, 1950 E. FROMMER 2,530,162

THREADING TOOLHOLDER I Filed May 24, 1946 2 Sheets-Sheet l I u ventor fzfgene Fmmmen Nqv. 14, 1950 E. FROMMER THREADING TOOLHOLDER 2 Sheets-Sheet 2 Filed May 24, 1946 WWW m Patented Nov. 14, 1950 OFFICE THREADING TOOLHOLDER Eugene Frommer, New York, N. Y.

Application May 24, 1946, Serial No. 672,062

2 Claims.

This invention relates to new and useful improvements and structural refinements in tool holders, more specifically, to a holder of the character herein described, such as may be effectively and conveniently employed for the holding of taps and dies in automatic or hand screw ma- .chines, lathes or the like.

The principal object of the invention is to provide a holder which is self-releasing in operation, that is, in which the threading tool will be fed onto the work to a predetermined extent, whereupon the action thereof will be automatically Suspended in readiness for return to its normal position at the commencement of the next working stroke.

A further object of the invention is to provide a holder which may be readily adjusted for satisfactory operation by persons of limited skill and which, once adjusted, will continue to function without the necessity of constant attention.

Another object of the invention is to provide a holder in which the tools, such as the dies or taps, may be readily applied or removed.

An additional object of the invention is to provide a holder which, as a whole, may be easily attached to the machine with which it is used.

A still further object of the invention is to provide a holder which is simple in construction and operation, and which will not easily become damaged.

With the above more important objects in view, and such other objects as may become apparent as this specification proceeds, the invention consists essentially of the arrangement and construction of parts as illustrated in the accompanying drawings, in which:

Figure l is a side elevation of the invention, illustrating the same at the commencement of the working stroke;

Figure 2 is a central, longitudinal, cross sectional view of the subject shown in Figure 1;

Figure 3 is a Side elevation view of the invention, but showing the same at the completion of the working stroke;

Figure 4 is an end view taken in the direction of the arrow 4 in Figure 3, and

Figure 5 is a fragmentary side elevation similar to that shown in Figure 3, but illustrating a relatively different working position of the tool receiving socket with respect to the supporting head.

Like characters of reference are used to designate like parts in the specification and through- ;tion a supporting head designated generally by,

the reference character l0, and consisting of a disk-like plate ll, provided on one side thereof with an integral shank l2, which may be tapered as shown, if desired. The remaining side of the plate H is formed integrally with a cylindrical spigot l3 terminating in a screw threaded portion It of a relatively smaller diameter, the purpose thereof being hereinafter more fully set forth.

It will be noted that the shank I2 and the spigot I3 are axially aligned with respect to the plate I l.

A cylindrical tool receiving socket I5 is provided with an axial bore Hi, this terminating at one end in an inturned flange ll, while its remaining end is counterbored as at l8.v

The socket I5 is slidably and rotatably positioned on the spigot l3, and is retained in position by means of a suitable nut l9, threaded onto the portion I4. It should be understood that the nut I9 is complementary to the cross section of the bore 16, the nut in effect, functioning as a bearing on which the socket l5'may rotate. A compression spring 20 is interposed between the nut 19 and the flange l'l, whereby the socket I5 is normally urged against the plate H.

The counterbore I8 is, of course, adapted to receive a suitable tap or die 21, which is removably retained in position by a pair of diametrically opposed set screws 22, provided in the bodyof the socket l5.

The plate H is formed with the apertures '23, and a pin 24 is positioned in each of these apertures, as will be clearl apparent from the accompanying drawings. It will be noted that the pins 24 are secured in position by suitable set screws 25, and the pins 24 project on one side of the plate I! to a predetermined degree, as is indicated by the reference character 26.

A lug 21 is welded, or otherwise similarly secured, to the periphery of the plate H, the lug 27 being configurated substantially as shown and provided with a bore 28. A pawl 29, provided with a cam surface 30, is pivotally mounted also on the periphery of the plate I l, adjacent the lug 27, the mounting of this pawl being provided by means of a suitable pivot bolt or screw 3].

The pawl 29 is formed with a recess 32, this being adapted to receive one end of an adjusting screw 33. In eifeot, the latter assumes the form of a simple rod, pivotally connected to the pawl 29 by a pin 34,- the rod 33 passin freely through the bore. 28 of the lug 2l', and terminating at its remaining end with a screw threaded portion adapted to receive the adjusting nut 35. A flat washer 36 is positioned adjacentthis nut, and a compression spring 31 is placed on the rod 33, between the washer 36 and the aforementioned lug 21. It will be noted, that in this manner, the pawl 29 will be normally urged toward the lug 21, as is best shown in Figures 1 and 3.

When the invention is placed in use, the shank I2 is mounted in the tailstock or turret of the lathe, or the like, with which the invention is used. It should be understood, that the supporting head In is thus non-rotatably held in the tailstock, and the holder, at the commencement of the working stroke will assume the position indicated by the accompanyin Figure 1.

The work to be threaded is, of course, clamped in the chuck of the machine, and the work and the tool holder are advanced together until the die or tap 21 engages the work and commences its initial cut thereon.

In use of the present invention, the same is applied to a turret or tailstock (not shown) and is advanced during the threading operation until it is nearly completed when a fixed adjustable stop (not shown) is used to prevent further feed movement of the turret but due to the yielding joint of the present holder, shown in Figure 2, the threading continues for a short time and advances holder IS with respect to part It which causes the socket 9 to clear the clutch pins 2% to stop the threading operation because now holder l rotates with the work. Reversal of rotation of the work (not shown) will render pawl clutch parts 30, 42 efiective to screw holder off the work which is usually accompanied by a retraction of the turret by its own feed mechanism (not shown) to restore the clutch pins 24 in the mating sockets 39 to reset the holder for the next threading operation.

If the machine is not stopped or reversed at this time, the rotation of the socket 15 in the direction of the arrow 38 may continue without damage, and during each revolution the cam surface of the pawl 29 will engage a cam surface 4| of a dog 42, which is mounted on the lateral wall of the socket 15. It will be noted that the cam surfaces 4|, 30 of the dog 42 and the pawl 29 respectively, are so disposed that the pawl 29 will be tripped during each revolution of the socket [5, as is best shown in the acconn panying Figure 5.

The machine may then be manually or automatically reversed to rotate in the direction of the arrow 43, and as soon as the dog 42 contacts the pawl 29 as shown in Figure 3, the rotation of the socket IE will be prevented. The tool 2! and the associated socket 5 will then proceed to withdraw itself from the work, until the pins 24 are again received in the apertures 39 and the device, as a whole, assumes the position illustrated in Figure 1. The holder will, of course, be then in readiness for the next working stroke in the threading operation.

The depth of thread on the work may be accurately governed to a predetermined degree by loosening the set screws 25 and adjusting the extent 26 to'which the pins 24 protrude from the plate I].

It is believed that the advantages and use of the invention will be clearly understood from the foregoing disclosure and accordingly, further description thereof at this point is considered unnecessary.

While in the foregoing there has been shown and described the preferred embodiment of this invention it is to be understood that minor changes in the details of construction, combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as claimed.

What I claim as my invention is:

1. A tool holder of the class described, comprising in combination, a supporting head comprising a disk-like plate, a shank on one side and a cylindrical spigot at the remaining side of said plate, a cylindrical tool receiving socket slidably and rotatably mounted on said spigot, a compression spring embracing said spigot and yieldingly urging said socket against said plate, said socket being formed with a plurality of apertures in one end thereof, a plurality of slidably adjustable pins on one side of said plate in registry with said apertures, said pins being removably receivable in said apertures, a cam surfaced dog on the outer surface of said socket, a pawl pivotally mounted on the periphery of said plate, and tension adjustable spring means disposed exteriorily of the head and the socket and acting on said pawl, said pawl engaging said dog to limit rotation of said socket clockwise on said spigot, said pawl having a flat surface for engaging the dog when the pins are aligned with said apertures to permit movement of the socket toward the plate when the socket is rotated clockwise on said spigot, and said pawl having a cam surface for riding against the cam surface of said dog when the socket is rotated counterclockwise on said spigot.

2. A tool holder comprising a supporting plate, a cylindrical spigot carried by said plate, a cylindrical tool receiving socket slidably and rotatably' carried by the spigot, a, coil spring normally urging the socket against the plate, said socket having a plurality of circumferentially spaced recesses in one end, a plurality of adjustable clutch pins carried by the plate removably engaging the recesses in said socket, a fixed support lug carried by the plate, a pawl pivotally carried by the plate having a cam surface and a bearing surface, a holding rod slidably carried by the support lug, one end of said holding rod being pivoted to the pawl, the remaining end of said rod being threaded, a nut adjustably carried by the threaded end of said rod, a coil spring carried by the rod and biased between the lug and nut for normally urging the pawl against the lug, and a dog fixed to the socket, said dog having a bearing surface for engaging the bearing surface of said pawl to limit the rotation of the socket in one direction and to align the pins with the recesses, and a cam surface for riding past the cam surface of the pawl during rotation of the socket in an opposite direction. EUGENE FROMMER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS v Date 

